1. Field of the Invention
The present invention relates to an image forming apparatus having a thermal fixing apparatus.
2. Related Background Art
In recent years, an image forming apparatus having a thermal fixing apparatus, particularly, a laser printer, are in wide use in many offices and homes in association with the miniaturization and light weight of the apparatus.
In the printer using the thermal fixing apparatus, a print quality of an output image is excellent as compared with print qualities of the other recording apparatuses such as thermal printer, ink jet printer, and the like and is an apparatus which is indispensable at present.
The thermal fixing apparatus has a heater of a thermal energy within a range from tens of W to a few KW. Hitherto, to keep a predetermined temperature so long as a power supply of the apparatus is on, it is necessary to control the on/off operation of the heater.
Further, to prevent an influence on the whole apparatus by a heat of the thermal fixing apparatus, the cooling fan and the like also need to be constantly driven.
On the other hand, so long as the power supply to the apparatus is on, the heater as a thermal source and the driving system such as a fan and the like are also simultaneously turned on.
As mentioned above, however, in a situation such that a number of laser printers are widely spread in homes and offices, in the case of using the apparatus for a period of time from a few months to a few years without turning off a power supply of the apparatus, there is a problem on safety to a thermal source and there is also a disadvantage such that a life and the like of a driving system such as a cooling fan and the like are also reduced.